Multi-speed gearbox with high torque ratio and the drive axle made therewith

Abstract

An electric drive axle assembly of a vehicle includes an electric motor having an output shaft. At least one of a gear and a planetary gear assembly is coupled to the output shaft of the electric motor. The at least one of the gear and the planetary gear assembly is coupled to a differential mechanism configured to transfer torque to two axle shafts of the vehicle. The electric drive axle assembly configured to produce a plurality of speed ratios between the electric motor and the differential mechanism.

What is claimed is: 
     
       1. An axle assembly, comprising:
 an electric motor having an output shaft; 
 at least one of a gear and a first planetary gear assembly connected to the output shaft; 
 a differential mechanism connected with the at least one of the gear and the first planetary gear assembly, wherein the differential mechanism is connected to at least one axle shaft; 
 a first clutch assembly connected with at least one of the output shaft and the differential mechanism, wherein an engagement of the first clutch assembly produces a first speed ratio; 
 a second clutch assembly connected with at least one of the output shaft and the differential mechanism, wherein an engagement of the second clutch assembly produces a second speed ratio; and 
 a compound idler assembly connected to at least one of the output shaft and the differential mechanism. 
 
     
     
       2. The axle assembly of  claim 1 , further comprising a third clutch assembly connected with at least one of the output shaft and the differential mechanism, wherein an engagement of the third clutch assembly produces a third speed ratio. 
     
     
       3. The axle assembly of  claim 1 , wherein the compound idler assembly is disposed offset and parallel to the output shaft of the electric motor. 
     
     
       4. The axle assembly of  claim 1 , wherein at least one of the first planetary gear assembly, the first clutch assembly, and the second clutch assembly is disposed on the compound idler assembly. 
     
     
       5. The axle assembly of  claim 2 , wherein one of the first clutch assembly, the second clutch assembly, and the third clutch assembly is connected to the first planetary gear assembly. 
     
     
       6. The axle assembly of  claim 1 , wherein the first planetary gear assembly is selectively connected to the output shaft by one of the first clutch assembly and the second clutch assembly. 
     
     
       7. The axle assembly of  claim 1 , wherein the at least one axle shaft is coaxially aligned with the output shaft. 
     
     
       8. The axle assembly of  claim 1 , further comprising a second planetary gear assembly connected to the output shaft. 
     
     
       9. The axle assembly of  claim 8 , wherein the second planetary gear assembly is selectively connected to the output shaft by one of the first clutch assembly and the second clutch assembly. 
     
     
       10. The axle assembly of  claim 8 , wherein the second planetary gear assembly is connected to the first planetary gear assembly. 
     
     
       11. The axle assembly of  claim 8 , further comprising a third planetary gear assembly connected to the at least one axle shaft. 
     
     
       12. The axle assembly of  claim 11 , further comprising a fourth planetary gear assembly connected to the at least one axle shaft. 
     
     
       13. A method, comprising:
 providing an axle assembly including:
 an electric motor having an output shaft; 
 at least one of a gear and a first planetary gear assembly coupled to the output shaft; 
 a differential mechanism connected with the at least one of the gear and the first planetary gear assembly, wherein the differential mechanism is connected to at least one axle shaft; 
 a first clutch assembly connected with at least one of the output shaft and the differential mechanism, wherein an engagement of the first clutch assembly produces a first speed ratio; 
 a second clutch assembly connected with at least one of the output shaft and the differential mechanism, wherein an engagement of the second clutch assembly produces a second speed ratio; and 
 a third clutch assembly connected with at least one of the output shaft and the differential mechanism, wherein an engagement of the third clutch assembly produces a third speed ratio; and 
 causing the engagement of one of the first clutch assembly and the second clutch assembly. 
 
 
     
     
       14. The method of  claim 13 , further comprising causing the engagement of the third clutch assembly. 
     
     
       15. An axle assembly, comprising:
 an electric motor having an output shaft; 
 a first gear in a planetary gear assembly rotationally connected to the output shaft; 
 a differential mechanism rotationally connected with at least one of the first gear and the first planetary gear assembly, wherein the differential mechanism is rotationally connected to an axle shaft; 
 a first clutch assembly including:
 a first plurality of clutch plates rotationally connected to the output shaft; and 
 a second plurality of clutch plates rotationally connected to the differential mechanism, wherein an engagement of the first clutch assembly produces a first speed ratio; and 
 
 a second clutch assembly rotationally connected to the differential mechanism, wherein an engagement of the second clutch assembly produces a second speed ratio. 
 
     
     
       16. The axle assembly of  claim 15 , further comprising an idler shaft rotationally connected to at least one of the output shaft and the differential mechanism. 
     
     
       17. The axle assembly of  claim 16 , wherein the output shaft, the idler shaft, and the axle shaft are offset from one another. 
     
     
       18. The axle assembly of  claim 15 , wherein the second clutch assembly includes a plurality of plates connected to a second gear in the planetary gear assembly. 
     
     
       19. The axle assembly of  claim 18 , wherein the second gear is a ring gear.